Portable burglar-alarm



F. BACON. PORTABLE BURGLAR ALARM.

APPLICATION FILED NOV.23, I920.

Patented Aug. 30, 1921.

INII/ENTOR WMMZJ ATTORNEY UNITED STATES;

FRANK BACON, OF BAYSIDE, NEW YORK.

PORTABLE BURGLAR-ALARM.

I Specification of Letters Patent. Patented Aug. 30, 1921.

Application filed November 23, 1920. Serial No. 425,977.

To all whom it may concern: V

Be it known that I, FRANK BACON, a citizen of the United States, residing in the Town of Bayside, in the county of Queens and State of New York, have invented certain new and useful Improvements in Portable Burglar-Alarms, of which the following is a specification.

The principal object of my invention is to provide a portable burglar alarm that may be readily secured to the inner knob of the door of a room in a hotel, apartment or other building to warn the occupant of an attempt of a burglar to enter it. The device is'simple in construction, compact in assen1- bly and eflicient in 4 operation. It may be conveniently carried in a travelers hand bag, and may be quicklyv appliedto the inner knob of the door of the room one has engaged in a hotel or -other building. Should a burglar attempt to enter that room, the device will be automatically operated when the knob is turned, to instantly apprise the occupant of that fact.

In the accompanying drawings, Figure 1 is a vertical elevation, partly in section, of my device applied to theinner lmob of a door. Fig. 2 is a cross sectional view of said device taken on the line a'a Fig. 1. Fig.

3 is a perspective view of the spring clamp on the door knob. Fig. 4 is a side elevation of a portion of the mechanism showing the releasing pawl. Fig. 5 in a vertical elevation of said device showing the release of the ball to set off the alarm after the knob has been turned.

Throughout the specification and draw ings, similar reference characters denote corresponding parts.

Referring to the accompanying drawings,

the numeral 1 designates the inner knob, and 2 the outer knob of a door 3. The numeral 4 designates a supporting member which is secured at its lower end to spring clamping bands 5 adapted to grip the inner bell casting 8 which be of any suitable size and shape.

Projecting upwardly from the top of the bellcasting is a'boss 9 which is cup-shaped to support a ball 10 when the casting isin a vertical position. I

Rigidly secured to the rod 5 is a ratchet 11.. A lug 12 projects from the supporting member 4 to support a pawl 13 which is loosely mounted on a pin 14 secured in said lug. This pawl 13 is pressed by a spring 15 into engagement with the teeth of the ratchet 11 to permit the rotation of the latter in one direction only.

The inner end of a Spi al spring 16 is secured by a shouldered pin 17 to the rod15 This spiralfspring is inclosed in a. cupsh'apedhousing 18v which is rigidly connected to a gear 19. The gear and housing are free to rotate around the rod 5; The outer end of the spiral spring 16 is attached to a shouldered pin 20 which projects inwardly from the wall of the housing 18.

A second lug 21' projects outwardly from the supporting member 4' to act as a bearing for a shaft 22. This shaft carries on its upper end a toothed pinion 23 which meshes with, and is driven by, the gear 19. At its lower end the shaft 22 carries a toothed member 24 adapted to oscillate the escapement 25. The latter is loosely mounted on a pin 26, projecting from the supporting member 4. Rigidly secured to the escapement 25 is a clapper rod 27 terminating at its outer end in a clapper 28. The latter is arranged to strike the inner surface of the bell 8 when the escapement is oscillated. (See Figs. 1 and 2.)

For the purpose of normally holding the clapper rod 27 from oscillation, there is provided a trip pawl 29. A spring 30 presses a notched portion 31 in the trip pawl against the clapper rod 27 to prevent it from oscillating. This trip pawl 29 is supported by a pin.32 which projects from the main supporting member 4. At its free end, the trip pawl 29 has a hole 33 to receive one end of a trip cord 34, the other end of which is secured to aneye 35 on the ball 10. V (See Figs.

1 and 4.)

In operation, the spring 16 is Wound in the following manner. The supporting member 4 is held firmly and the bell casting 8 is rotated. The rotation of the bell rospring 16 is secured by the pin 17. The bell 8 is rotated in that direction which per-' mits the teeth on the ratchet 1-1 to pass under the pawl 13, which restrains the rod 5? from rotating in the opposite direction aft-er the spring 16 has been wound up.

The device is now secured in a vertical position on the inner door knob 1, by snapping the clamp 5 over it. The ball 10 is then placed on top of the boss 9. Should the outer knob 2 be rotated by a burglar to the position shown in Fig. 5, the center of gravity of the ball 10 will be changed sulliciently to cause it to fall from. the boss 9 to pull the trip pawl 29 out of engagement with the clapper rod 27. This permits the latter to be oscillated by the toothed member 24, which is turned by the pinion 23 that is driven by the gear 19 secured to the outer end of the spiral sprin 16. The oscillation of the clapper rod 2'! will cause the clapper 28 to intermittently strike the interior surface of the bell 8, for the purpose of audibly warning the occupant of the room, that a burglar is a*- tempting to enter it. He is thus" warned in ample time to defend himself and protect any property that might be stolen.

I do not wish to be limited to the details of construction and arrangement herein shown and described, and any changes or modifications may be made therein within the scope of the subjoined claims.

Having described my invention, I claim:

1. A device of the type described comprising a bell having an open bottom, an upright supporting member projecting through the open bottom of said bell, for attachment to the inner top portion of the latter, a spring clamp secured to the lower end of said supporting member for attachment to the inner the inner top portion of the latter, a spring clamp secured to the lower end of said supporting member for attachment to the inner knob of a door, a clapper operatively secured to said supporting member within the bell, for oscillation in contact with the inner surface of the latter, spring means also secured to said upright member within the bell, for oscillating said clapper, means within the bell for holding said clapper against oscillation, a ball mounted on top of said bell, and a flexible connectionfbetween said ball and clapper holding means whereby, when the bell is tipped, said ball will fall to pull the holding means out of engagement with said clapper, for the purpose specified. j

In testimony whereof I have hereunto set my hand'this 19th day of November, 1920.

. FRANK BACON. 1

Witness:

AMANDA H. MILLER. 

